Formation of Thiol-Functionalized Silica Films by Layer-by-Layer Self-Assembly and Biomimetic Silicification

摘要

Recent advances in the area of biomimetic silicificationpromise a new route to cost-effective and low-energy control of silica materials. Various structures of silica, such asnanoparticles and thin films, have already been synthesized under mild conditions (ambient pressure, room temperatureor below, and near neutral pH values) that mimic the physiological conditions used in nature. Moreover, bio-compatible control of silica expanded the use of silica to interfacing silica with biological entities, such as living cells. Cells, such as yeast, bacteria, and mammalian cells, as well as proteins have been immobilized in inorganic silica matrices. Especially, we encapsulated individual living cells with silica, by combining bio-friendly layer-by-layer technique and biomimetic silicification. In further manipulations of the silica-cell interface, functionalizations of silica under biocompatible conditions would be essential for the realization of biosensor circuits, lab-on-a-chip systems, and bioreactors, as well as for fundamental studies in cell biology. Methods for the modification of silica surfaces are well-established for the applications of mesoporous zeolites and wettability control. However, the reported methods for introducing functional groups to silica surfaces mostly need chemical treatments that lack the biocompatibility. Herein, we report a simple but versatile approach to the introduction of chemical functional groups to biomimetic silica structures, with an aim of the application to living cells.